yoak-arduino-adc

void setup() {
  // initialize serial communication at 9600 bits per second:
  delay(5000);
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (5.0 / 1023.0);
  // print out the value you read:
  Serial.print("Voltage : ");
  Serial.print(voltage);
  Serial.println(" V ");
delay(1000);
}